A known deployable nozzle for a rocket engine comprises at least a stationary divergent segment and a movable divergent segment that is coaxial about the stationary divergent segment and suitable for moving along the stationary divergent segment from a retracted position towards a deployed position.
That type of deployable nozzle is generally fabricated in such a manner that its walls are as thin as possible, within limits set by mechanical strength and ability to withstand high temperature, in order to reduce its weight and thus optimize the performance of the engine on which it is mounted. Nevertheless, the movable divergent segment is particularly flexible while it is in the retracted position, such that the vibration to which it is subjected can lead to high levels of mechanical loading that can degrade it to such an extent as to prevent it from operating properly. For example, while the nozzle is retracted between two stages of a rocket, the vibration to which it is subjected during launching of the rocket can crack or even break the movable divergent segment.
An object of the present invention is to remedy the above-mentioned drawbacks, at least in part.